PLEASE HELP: noise (hiss, buzz) problem
I've recently finished installing a computer stereo system in the 2000 GS400 but couldn't get rid of the hissing/buzzing noise from the front & rear speakers. For almost a month, I've searched/read from many forums and tried all the tips/suggestions but still couldn't solve the problem. Here's my system setup:
Battery: Optima Yellow 34/78
Power Supply: Opus 150W DC PSU (a flip-switch and a relay were used between the ACC and PSU)
Computer: EPIA M 1000 (installed in glove compartment)
Monitor: DSCustoms TouchScreen (powered by Opus)
Soundcard: SB Extigy USB (powered by Opus)
Amplifiers: Kicker 600.4 and Kicker 1200.1 (installed in trunk)
Speakers: front: Focal 130V components, rear: CDT 61 components
Subwoofers: two Infinity Kappa Perfect 12.1 DVC in a bandpass enclosure
Wirings: Stinger power and speaker cables, Monster Cable 20-ft "mini 1/8" to RCA" cables
From reading from various posts and tutorials, I thought the noise is caused by a ground loop. But the noise was still there even when I connected the power & ground of the Kicker 600.4 amp directly to the pos. & neg. battery posts, all the settings were set to minimum and the signal input was muted by this method (http://akamaipix.crutchfield.com/gra...p-diagnose.gif).
Can I assume there should be NO noise if the amp is grounded directly to the battery instead of car metal chassis? Will installing a capacitor help? Is running a long GROUND cable from battery to trunk recommended?
I would really appreciate your replies with any hints, tips, suggestions, etc. Please help ending my nightmare !!! Sorry for the long post.